In which reaction does the smallest percentage change in volume occur?

Question

a) C3H8 (g) + 5O2(g) ---> 3CO2(g) + 4H2O(l)
b) 4NH3(g) + 3O2(g) ----> 2N2(g) + 6H2O(l)
c) CH4(g)+ 2O2(g) ----> CO2(g) + 2H2O(l)
d) 2H2S(g) + SO2 (g) ----> 3S(s) + 2H2O(l)

The correct answer is A, but how do i do this?

Answer 1

sorry i submitted the question twice i think .